How to debug shared librarys with GDB?

The simplest method (maybe the only method) is:

1. Set a break point in main ()

2. List the source code or symbol name of the shared library, and set the break point.

 

You cocould use add-symbol-file to load the symbols of the shared library. use LDD, you can see the link address of this shared library, this is the address for the add-symbol-file command. but even you specify the correct address, because at that time, this library has not been loaded in memory, you can not set a break point. it will prompt such error "cannot access memory at address 0x00xx00xx ".

 

Another way, you can set a signal handler in GDB, e.g ., (GDB) handle SIGINT stop. then when you press Ctrl + C, the debugger will intercept the SIGINT signal to debuging application, then it will stop, you can set break point at that time. use kill-l, you coshould list all signals in your system.